One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10)(11,15)(12,18)(13,21)(14,16)(17,20)(19,24)(22,23)(25,26,30,32)(27,33,36,31)(28,29,37,39)(34,38,40,35)(1,3,5,4)(2,6,7,8)(9,11)(10,15)(12,19)(13,22)(14,20)(16,17)(18,24)(21,23)(25,27,30,36)(26,31,32,33)(28,34,37,40)(29,35,39,38)(10,16)(11,20)(18,22)(19,21)(26,32)(28,37)(31,33)(34,40) involution — undirected(9,11)(10,17)(12,21)(13,22)(14,20)(15,16)(18,24)(19,23)(25,28)(26,29)(27,34)(30,37)(31,35)(32,39)(33,38)(36,40) involution — undirected(1,2)(3,6)(4,8)(5,7)(9,12)(10,18)(11,21)(13,15)(14,23)(16,22)(17,24)(19,20)(25,27)(26,33)(28,34)(29,38)(30,36)(31,32)(35,39)(37,40) involution — undirected(1,4,5,3)(2,6,7,8)(9,13,14,24)(10,19,16,21)(11,22,20,18)(12,17,23,15)(25,29)(26,28)(27,35)(30,39)(31,34)(32,37)(33,40)(36,38)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.