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