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