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