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