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