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