One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,5)(4,7)(6,8)(11,17)(14,20)(18,23)(21,24)(25,26)(27,35)(28,32)(29,33)(30,34)(31,38)(36,40)(37,39) involution — undirected(1,2,5,3)(4,6,8,7)(9,10,13,16)(11,14,17,20)(12,15,19,22)(18,21,23,24)(25,26,30,34)(27,31,38,35)(28,32,29,33)(36,39,37,40)(1,2,5,3)(4,6,8,7)(9,11)(10,14)(12,18)(13,17)(15,21)(16,20)(19,23)(22,24)(25,26)(27,31)(28,32)(29,33)(30,34)(35,38)(36,39)(37,40)(2,3)(6,7)(9,10)(11,14)(12,15)(13,16)(17,20)(18,21)(19,22)(23,24)(25,27)(26,31)(28,36)(29,37)(30,38)(32,39)(33,40)(34,35) involution — undirected(1,3,5,2)(4,7,8,6)(9,11)(10,14)(12,18)(13,17)(15,21)(16,20)(19,23)(22,24)(25,28,30,29)(26,32,34,33)(27,36,38,37)(31,39,35,40)(1,4)(2,6)(3,7)(5,8)(9,12,13,19)(10,15,16,22)(11,18,17,23)(14,21,20,24)(25,29,30,28)(26,33,34,32)(27,37,38,36)(31,40,35,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.