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