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