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