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