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